It is known to provide concentrated chemical solution for introduction into liquid systems or processes for a variety of purposes. For example, chemical concentrates, including mixtures of different chemistries, are diluted to provide solutions for water treatment and prevention of scale and deposit accretion and buildup in tanks, boilers and cooling towers and in both open and closed water systems, for industrial cleaning, for detergent production in dishwashing systems and washing machines, for other cleaning and sanitizing purposes, and for continual and periodic cleaning and maintenance functions in a variety of applications.
Typically, a “dissolver” for dissolving or diluting a chemical is used to receive a chemical concentrate, dissolve or dilute it, and introduce the resulting solution to a system for treatment.
Specific disclosures of such prior apparatus and processes are found, for example, in U.S. Pat. Nos. 2,371,720; 3,383,178; 3,595,438; 4,858,449; 4,964,185; 5,137,694; 6,441,073; 6,418,958; 6,820,661; in United States Patent Publication Nos. US2007/0269894 and US2010/0025338. Each of these is expressly incorporated herein by reference and is a part hereof as if fully set out herein. Copies of these are attached and are a part hereof.
Moreover, it will be appreciated that systems for producing a concentrated chemical solution and for delivering that solution to a system for use are typically designed for specific applications due to the parameters of the system to be treated; all the way from washing machines on one hand to closed loop water tower and processes or building cooling systems on the other. Volumes, pressures, temperatures, water chemistries, chemical solutions required and many other parameters require significantly different dissolving and delivery systems.
Another consideration in this field is the state or form of the concentrated chemical used to form the treatment solution. Concentrated chemicals can be provided in either a concentrated liquid form or in a “solid” form. The term “solid” is herein used to differentiate or distinguish from other forms of chemical such as granules, flakes, beads, free flowing aggregates, particulates, powder and liquid. The terms “solid” and “solid chemical feed unit” as used herein are thus intended to refer to a monolithic mass in a freestanding, structural shape which may be formed by any suitable process including but not limited to compression, casting, molding and other processes. When dissolving a chemical in solid form, it is typical to spray a pattern of water onto the face of the solid chemical.
Comparisons of liquid to solid concentrated chemicals are set out in United States Patent Pub No. US2010/0025338, incorporated herein by reference.
When considering use of chemicals in solid form such as solid chemical feed units, particularly in the treatment of larger water systems such as heating and cooling systems, relatively larger amounts of concentrated chemical are required as compared to smaller volume systems. Regardless of the size of the solid chemical feed unit system, the feeding and dissolving process must be consistent so the chemical solution produced by the dissolving process is accurate and consistent.
Potentially interfering with these considerations is the nature of the interface of the solid chemical feed unit being dissolved by a water spray. While it is important to consistently dissolve chemical from the solid feed unit at a forward surface of that unit, it is also desirable to maintain chemical behind that surface as dry as possible to prevent such wetting and caking as would prevent consistent presentation of chemical at a location where the water spray most effectively and uniformly dissolves the chemical. Said in another way, if chemical in a solid feed unit behind the interface of the forward surface and the water spray becomes wet or cakes, feeding or movement of the solid chemical feed unit toward the spray interface can be adversely affected, as well as the surface of the solid chemical receiving the spray pattern. This can result in stoppages, in inconsistent solution production and in production of widely varying solution content adversely affecting the efficiency and viability of the treatment desired.
In another aspect of solid chemical feed unit dissolving, it is desirable that operator time and attendance at the dissolver be reduced, even while the dissolver must be capable of producing large amounts of chemical solution for large volume applications. This requires operable disposition of significant numbers of solid chemical feed units in the dissolver. While a plurality of such solid chemical feed units might be stacked, such as a small plurality of such solid chemical feed units in a much lower capacity dissolver (like four solid chemical feed units provided in a gallon-sized bucket), it is desired to provide apparatus and processes for handling much larger amounts of solid chemical feed units for much larger applications without the frequent operator attention required for gallon-sized solid chemical feed unit fills in such larger units.
It is also desirable to provide solid chemical feed unit dissolvers facilitating use of multiple solid chemical feed units without damage from dropping solid chemical feed units one onto another, and without feeding or consistency issues arising from wetting or caking. For example, in some applications, it may be desirable to accommodate fills of about fifty to two hundred pounds or so of total solid chemical feed unit weight where large volume systems are to be serviced. And it is desired to do so within a small dissolver footprint, but in a stable application.
Finally, it is desirable to provide the capability of observing the feed units in the dissolver as an indication of current status and the need to replenish the feed units for consistent treatment. Typical small capacity dissolvers do not provide such observation capacity.